@cast

---@cast varName TypeExpression
---@cast varName +TypeExpression   -- add type to union
---@cast varName -TypeExpression   -- remove type from union

---@type string | number
local value = getValue()

if type(value) == "string" then
    ---@cast value string
    print("Length:", #value)  -- ✅ narrowed to string
end

---@type Player | nil
local ply = findPlayer(id)

---@cast ply Player  -- assert not nil (removes nil from the union)
ply:ChatPrint("Found!")  -- ✅ no need-check-nil warning

---@type Entity
local ent = ents.GetByIndex(1)

---@cast ent Player  -- assert that ent is actually a Player
ent:GetFriends()     -- ✅ Player method available

---@type string
local val = "hello"

---@cast val +number  -- val is now string | number

---@type string | number | nil
local val = getVal()

---@cast val -nil  -- removes nil, val is now string | number

---@type table
local data = getData()

---@cast data { id: number, name: string }
print(data.id)    -- ✅
print(data.name)  -- ✅